The British Museum said Wednesday that a member of its staff has been dismissed after items dating back as far as the 15th century B.C. were found to be missing, stolen or damaged.

The museum said it has also ordered an independent review of security and a “vigorous program to recover the missing items.”

The stolen artifacts include gold jewelry and gems of semiprecious stones and glass dating from the 15th century B.C. to the 19th century A.D. Most were small items kept in a storeroom and none had been on display recently, the museum said.

"Our priority is now threefold: first, to recover the stolen items; second, to find out what, if anything, could have been done to stop this; and third, to do whatever it takes, with investment in security and collection records, to make sure this doesn't happen again," said George Osborne, the museum's chair.

"This incident only reinforces the case for the reimagination of the museum we have embarked upon," Osborne said.

The museum said that legal action would be taken against the dismissed staff member and that the matter was under investigation by London's Metropolitan Police Service.

The 264-year-old British Museum is a major London tourist attraction, drawing visitors from around the world who come to see a vast collection of artifacts ranging from the Rosetta Stone that unlocked the language of ancient Egypt to scrolls bearing 12th century Chinese poetry and masks created by the indigenous people of Canada.

But the museum has also attracted controversy because it has resisted calls from communities around the world to return items of historical significance that were acquired during the era of the British Empire. The most famous of these disputes include marble carvings from the Parthenon in Greece and the Benin bronzes from West Africa.

Hartwig Fischer, the director of the British Museum, apologized and said the institution was determined to put things right.

“This is a highly unusual incident,” said Fischer said. "I know I speak for all colleagues when I say that we take the safeguarding of all the items in our care extremely seriously.''